Rotary engine

ABSTRACT

This rotary engine comprises a trilobe rotor mounted for rotation in a trochoidal chamber with opposed inlet and outlet ports of unique configuration located in the end walls of the trochoidal chamber for coaction with complemental propellant gas entrapment channels a in ends of the rotor, per se. A unique accelerator slider valve located in end walls of the trochoidal chamber permits variable timing of engine.

0 United States Patent [1 1 [111 3,877,848

Solem 1 Apr. 15, 1975 [54] ROTARY ENGINE 3,825,375 7/1974 Deane 418/61 A[76] Inventor: Edward L. Solem, 321 1 Euclid H i h Bl d Cl l d H i hPrimary ExammerWill1am L. Freeh Ohio 4 3 Assistant Examiner-O. T.Sessions 2] F1 d ec 5 1973 Attorney, Agent, or Firm--J. Gibson Semmes[21] Appl. No.: 421,851 [57] ABSTRACT This rotary engine comprises atrilobe rotor mounted [52] US. Cl. 418/61 A, 418/186 for rotation in atrochoidal chamber with 0 osed 51 1m.c|. F01c 1/02 inlet and Outletports of unique configuration ig [58] Field of Search 418/61 142 in theend walls of the trochoidal chamber for coac- [56] References Cited tionwith complemental propellant gas entrapment channels a m ends of therotor, per se. A umque accel- UNITED STATES PATENTS erator slider valvelocated in end walls of the trochoi- 3,193,188 7/1965 Bentele 418/142131 chamber permits variable timing of engine. 3,519,373 7/1970 Yamamoto418/61 A 3,762,842 10/1973 George 418/61 A 5 Claims, 8 Drawing FiguresHENTEEAFR 1 5i975 SBEET 2 BF 3 son 50 l m i FIG] no 3 l VALVE VL'OOACTUATION cowsmm 1 FIG 8 O G SOURCE TROCHOiDAL 1 A80 2 ROTOR g CONDENSER5g CHAMBER |20 VIZO ROTARY ENGINE BACKGROUND OF THE INVENTION Thisinvention relates to engines of the rotary piston type having atriangular-shaped or trilobe rotor travelling in an eccentricallydisposed path, wherein a rotor eccentric mounted on a power output shaftpermits the rotor to move with its apices constantly in sealing contactwith a surrounding trochoidal stator chamber. The basic geometry of suchengines is similar to that of the well-known Wankel internal combustionengine, nonetheless, the present is adapted to operate uponnon-combustible pressurized gasses, initially generated outside thetrochoidal stator chamber. The term gas herein connotes any gasifiednon-combustible fluid such as, but not limited to, steam.

DESCRIPTION OF THE PRIOR ART Pratt discloses a rotary steam engine inU.S. Pat. No. 3,452,643 in which conventional Wankel engine geometry hasbeen altered for steam driven operation through the use of pairs ofdiametrically opposed inlet and outlet ports located on either side ofthe minor axis of symmetry of the trochoidal chamber and in the sidewalls of the chamber. Assuming a constant pressure steam source is usedin the Pratt system, the fixed opening of the inlet ports in the sidewalls of the chamber determines the amount of time that the inlet portis open as each face of the rotor passes. This fixes the period of timein which the steam may expand freely against the rotor, causing it torotate, before the exhaust port is uncovered. If the inlet port remainsuncovered until just before the exhaust port is uncovered, the assumedconstant pressure source will act on the rotor continuously during thisportion of its movement, presumably providing a high torque performancewith low efficiency. If the inlet port remains uncovered for only ashort period of time, so that the steam may expand considerably againstthe rotor before the exhaust port is opened, low torque performance withhigh efficiency will be obtained. Since the minimum inlet port timing ofthe Pratt engine is fixed at the side wall of the trochoidal chamber,the torque level and efficiency are accordingly fixed for each operatingpressure. Thus, for more torque or power, one must vary the steampressure. or flux, per se.

SUMMARY OF THE INVENTION This invention provides a rotary engine inwhich output torque and efficiency may be varied for a given gaspressure by varying the size of gas inlet ports. Where constant torqueoperation is desired or where the engine is to be used with variablepressure steam sources, a fixed size inlet opening may be used toadvantage with the unique inlet and outlet port geometries of theinvention which coact with flow channels in ends of the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of engine withone head removed, depicting the rotor with one lobe at the bottom centerof the engine stator:

FIG. 2 is a perspective view of the rotor, per se;

FIG. 3 is a schematic view of the rotor in its stator chamber, depictingthe rotor displaced by ninety degrees from the position of FIG. 1;

FIG. 4 is a schematic view of the rotor in its stator chamber, the rotorbeing displaced by ninety degrees from the position of FIG. 3;

FIG. 5 is a perspective view of inlet valve slider plate and actuatorrod;

FIG. 6 is a perspective view of the inlet valve cover plate;

FIG. 7 is a vertical section of the inlet valve slider plate and inletvalve cover plate.

FIG. 8 is a schematic drawing of the rotary engine and compressed gassource.

DESCRIPTION OF THE PREFERRED EMBODIMENTS There follows a detaileddescription of the invention, reference being had to the drawings inwhich like reference numerals depict like elements of structure in eachof the several FIGURES.

FIG. 1 shows the block of the engine 100 which defines the trochoidalchamber at side wall 112 and may include cooling chambers or waterjackets 114.

Trilobe rotor 200 includes a ring gear 210 which is external of theeccentric bearing bore 220. Output shaft 300 includes a fixed eccentricor cam 320, eccentric 320 of output shaft 300 bearing in bore 220 of therotor. Fixed reaction gear 310 is concentric to the output shaft 300 andis attached to the end wall (not shown). Reference FIG. 2 apices seals230, connecting seals 340 and central seal 350 will seal the respectivegas expansion chambers of the rotor 200 from each other and from thecentral portion of said rotor. While not shown, the respective seals 340and 350 are in sealing contact on at least the three immediatelyadjacent joints 360 of each rotor chamber. Three straight radial sealsmay be set between the two; for the purpose. Whereas one face only ofthe rotor is shown, in FIGS. 1 through 4, both faces define likeexpansion chambers and all sealing means are disposed in coactivesealing relationship to contacting portions of the interior of theengine head, not shown.

Rotor 200 includes on each of its end faces three cutaway gas propellantflow channels 250 which in operation coact with the inlet and outletports of the head in a manner to be described. Assuming counterclockwise rotation of the rotor leading wall 252 of each flow channel250 extends from the outer periphery 240 of the rotor 200, inward towardthe rotor center, to a point 254 which is spaced in close proximity tobore 220. This spacing depends upon maximum inlet port size required fora particular engine operating characteristic and on such thickness ofmaterial that must remain between gas flow channels 250 and bore 220, topermit installation of respective seals 340. Trailing wall 256 of eachflow channel 250 is curved from point 254 to a point 258 located on theperiphery of the rotor such that 258 passes the counter clockwise edgeof 90 degrees after 252 passes the clockwise edge of 160. The preciseshape of the trailing walls and the radial depth of the leading wallsmay be varied, it will be appreciated, as required for a particularapplication; however, the geometry shown provides for a gradual closingof each stator inlet port as the rotor turns.

FIG. 2 being a perspective view of the rotor, indicates most clearly thepreferred geometry of rotor channels 250. There are three such channelson each side of the rotor in the preferred embodiment, to coact withfixed inlet and exhaust ports located in both end walls of the statorchamber. Nonetheless, it will be appreciated that said inlets could bedisposed on one end of the stator chamber and outlets on the other orboth on one end only, with flow channels disposed in the rotor asrequired, without departing from the spirit of this invention. Whileeach flow channel 250 is shown cut into the end surface of the rotor touniform depth on all sides this is a design variable, viz; the channelmay be cut shallower at the leading Wall 252 than at the terminus 258 ofthe trailing wall.

Withreference to the rotor 200 in the position shown in FIG. 1, at apexA, the disposition of the leading edge 152 of the stator inlet port tobe described is clearly defined as immediately adjacent and parallel tothe leading wall 252 of flow channel 250. Trailing edge 154 of thestator is parallel to leading edge 152 and spaced therefrom as shown,the spacing being a matter of design choice, depending upon the inletport size desired. Diametrically opposite stator inlet port is similarlylocated. Both inlet ports may be partially or fully opened, using aslider valve of the type shown in FIG. 5. Stator exhaust ports 180 areset in end walls of the stator chamber and lead through channels 182 toexhaust head connections I84.

Schematic drawing FIG. 3 shows rotor 200 in the stator chamber, definedby trochoidal side wall 112. The rotor is depicted as having rotated 90relative to the chamber, from the position of FIG. 1. See therelationshipof apices A, B and C in respective FIGS. 1, 3 and 4. Leadingedge 152 of exhaust port 150 is parallel and overlying the leading edges252 of rotor flow channels 250. Essentially, circumferential segments154 and 154 of the exhaust ports run perpendicular to edge 152 in amanner paralleling the counterparts of inlet ports 1 60.

In FIG. 4, the schematic of rotor 200 is again shown in thestatorchamber, defined by side wall 112. The rotor has again rotated another90 from the position in FIG. 3. The trailing edge 156 of exhaust port150 in stator head is immediately adjacent and parallel to the movingtrailing edge 256 of flow channel 250. The inboard edge 156 of theexhaust port is faced in between segment 154' and trailing edge 156, soas to permit adequate clearance with bore 220. The diametrically opposedexhaust port is similarly located relative to the bore 220.

FIGS. 5 to 7 are views of inlet port slider valve 400 and a combinationvalve body and inlet manifold adaptor 500 of the invention offering avariable inlet opening. The valve 400 may be parallel to the inlet port160. A combination valve body and inlet manifold adaptor 500 isremovably located on the end walls of the stator. When slider valve 400is fully inserted into the valve body and inlet manifold 500, no gascanenter the engine. As the adjustable slider valve 400 is withdrawnfrom the valve body and inlet manifold body 500, an opening to theengine, comprised of face 402 and edges 502, 504 and 504, is created.The size of this variable inlet opening is determined by the position ofthe slider valve 400. F ace 404 of slide valve 400 is flush with theinterior side of the stator end wall. The opening formed by edges 502,506, 508 and 508 is connected to the compressed gas source.

In the schematic of FIG. 8 there is depicted a steam driven rotaryengine embodying the invention. Pairs of inlet and exhaust ports arelocated in each head 120 at either end of the trochoidal chamber 110.The individual inlet slider valves are actuated by a suitable accelerator mechanism 400 such .as could be devised by one of ordinary skill inthe art. Steam or other gas from an essentially constant pressure source420 is directed through the inlet ports into contact with the channelsof the rotor. As slider valve plates may be extended outwardly, thestator inlet ports remain open for a progressively greater length oftime, relative to the movement of the rotor, yielding high torque, lowefficiency performance. As one establishes a smaller inlet opening, theinlet ports are shut more quickly by the coac- I tion with the rotorflow channels, yielding low torque, high efficiency performance. In theformer situation, the steam has little chance to expand and use itsenergy, to move the rotor; however, in the latter situation, arelatively long expansion cycle is obtained after the inlet opening isclosed which permits optimum use of the energy of the steam. Steamexhausts through the stator ports to condenser 430 from which condensateis returned to steam source 420. I

The invention in its essential concept is defined in the followingclaims: I

I claim: 1. A rotary engine comprising a. a stator block defining atrochoidal chamber, said stator block having closed ends, said endsdefining at least one propellant linear slot gas inlet of adjustablesize and at least one corresponding gas outlet,

disposed in operative relation to the said linear slot gas inlet; b. atrilobe rotor sealed within the trochoidalchamber between the endsthereof, said rotor containing of the channel being substantiallyparallel to the radius of the rotor, per se, the said channel beingdis-. posed in fluid flow relation to the respective gas inlet and gasoutlet;

c. a drive shaft having a cam engageable with the tri-. lobe rotor, theshaft bearing in ends of the trochoi-r dal chamber; and

d. a source of propellant gas connected to the propellant gas inletwherein by rotor operation, the gas channel of the rotor and gas inletsof the stator respectively define opposed gas expansion and contractionconfines, whereupon by movement of the rotor propellant gas is admittedthrough said gas inlet and said gas channel and a gradual expansion ofthe propellant occurs and is applied to the drive shaft cam by movementof the rotor about the trochoidal chamber.

2. The engine of claim 1, wherein the respective gas inlets of thestator are substantially rectangular, the

leading edge of each inlet being aligned with the radius of the leadingedge of the rotor gas channel in its path about the trochoidal chamberof the stator.

3. The engine of claim 1, wherein the gas inlet of the stator issubstantially rectangular, the leading edge of each inlet being alignedwith the radius of the leading edge of the rotor in its path about thetrochoidal chamber.

4. The engine of claim 3 wherein the respective channels of the triloberotor are three in number on at least channels of the rotor are three innumber on each side of the rotor and wherein the respective statoroutlet and inlet chambers are two in number on each side of the engine.

1. A rotary engine comprising a. a stator block defining a trochoidalchamber, said stator block having closed ends, said ends defining atleast one propellant linear slot gas inlet of adjustable size and atleast one corresponding gas outlet, disposed in operative relation tothe said linear slot gas inlet; b. a trilobe rotor sealed within thetrochoidal chamber between the ends thereof, said rotor containingcentrally disposed means to impart rotation to a drive shaft, said rotordefining at least one propellant gas channel upon at least one end facethereof, said propellant gas channel being of planar obtuse triangularvertical section, with curvalinear trailing edges defined by thechannel, and a leading edge of the channel being substantially parallelto the radius of the rotor, per se, the said channel being disposed influid flow relation to the respective gas inlet and gas outlet; c. adrive shaft having a cam engageable with the trilobe rotor, the shaftbearing in ends of the trochoidal chamber; and d. a source of propellantgas connected to the propellant gas inlet wherein by rotor operation,the gas channel of the rotor and gas inlets of the stator respectivelydefine opposed gas expansion and contraction confines, whereupon bymovement of the rotor propellant gas is admitted through said gas inletand said gas channel and a gradual expansion of the propellant occursand is applied to the drive shaft cam by movement of the rotor about thetrochoidal chamber.
 2. The engine of claim 1, wherein the respective gasinlets of the stator are substantially rectangular, the leading edge ofeach inlet being aligned with the radius of the leading edge of therotor gas channel in its path about the trochoidal chamber of thestator.
 3. The engine of claim 1, wherein the gas inlet of the stator issubstantially rectangular, the leading edge of each inlet being alignedwith the radius of the leading edge of the rotor in its path about thetrochoidal chamber.
 4. The engine of claim 3 wherein the respectivechannels of the trilobe rotor are three in number on at least one sideof the rotor and wherein the stator inlets are two in number and therespective stator outlets are likewise two in number, the inlets andoutlets being on at least one corresponding side of the engine.
 5. Theapparatus of claim 3, wherein the respective channels of the rotor arethree in number on each side of the rotor and wherein the respectivestator outlet and inlet chambers are two in number on each side of theengine.